Grain Yield Stability of Early Maize Genotypes

The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer's variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer's fields. Genotype and genotype × environment (GGE) biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments

Performance evaluation of quality protein maize genotypes across various maize production agro ecologies of Nepal

To identify superior quality protein maize genotypes for grain yield under different agro climatic conditions of terai and hill districts in Nepal, the coordinated varietal trials (CVT) were conducted at Dailekh, Doti, Salyan, Lumle and Pakhribas in 2013 and Salyan, Pakhribas and Kabre in 2014 during summer season and coordinated farmer’s field trials (CFFT) at Surkhet and Dailekh in 2013 and Salyan, Pakhribas and Khumaltar in 2014 during summer season. The experiment was carried out using randomized complete block design with three replications for CVT and CFFT. Across the locations and years the superior genotypes found under CVT were S01SIYQ, S01SIWQ-2 and Poshilo Makai-1 where as S99TLYQ-HG-AB, S99TLYQ-B and Poshilo Makai-1 were found superior genotypes under CFFT. The superior genotypes derived from CFFT will be promoted further for similar environments across the country

Performance evaluation of quality protein maize genotypes across various maize production agro ecologies of Nepal

ABSTRACT To identify superior quality protein maize genotypes for grain yield under different agro climatic conditions of terai and hill districts in Nepal, the coordinated varietal trials (CVT) were conducted at Dailekh, Doti, Salyan, Lumle and Pakhribas in 2013 and Salyan, Pakhribas and Kabre in 2014 during summer season and coordinated farmer's field trials (CFFT) at Surkhet and Dailekh in 2013 and Salyan, Pakhribas and Khumaltar in 2014 during summer season. The experiment was carried out using randomized complete block design with three replications for CVT and CFFT. Across the locations and years the superior genotypes found under CVT were S01SIYQ, S01SIWQ-2 and Poshilo Makai-1 where as S99TLYQ-HG-AB, S99TLYQ-B and Poshilo Makai-1 were found superior genotypes under CFFT. The superior genotypes derived from CFFT will be promoted further for similar environments across the country

Environmental sampling for typhoidal Salmonellas in household and surface waters in Nepal identifies potential transmission pathways.

IntroductionSalmonella Typhi and Salmonella Paratyphi, fecal-oral transmitted bacterium, have temporally and geographically heterogeneous pathways of transmission. Previous work in Kathmandu, Nepal implicated stone waterspouts as a dominant transmission pathway after 77% of samples tested positive for Salmonella Typhi and 70% for Salmonella Paratyphi. Due to a falling water table, these spouts no longer provide drinking water, but typhoid fever persists, and the question of the disease's dominant pathway of transmission remains unanswered.MethodsWe used environmental surveillance to detect Salmonella Typhi and Salmonella Paratyphi A DNA from potential sources of transmission. We collected 370, 1L drinking water samples from a population-based random sample of households in the Kathmandu and Kavre Districts of Nepal between February and October 2019. Between November 2019 and July 2021, we collected 380, 50mL river water samples from 19 sentinel sites on a monthly interval along the rivers leading through the Kathmandu and Kavre Districts. We processed drinking water samples using a single qPCR and processed river water samples using differential centrifugation and qPCR at 0 and after 16 hours of liquid culture enrichment. A 3-cycle threshold (Ct) decrease of Salmonella Typhi or Salmonella Paratyphi, pre- and post-enrichment, was used as evidence of growth. We also performed structured observations of human-environment interactions to understand pathways of potential exposure.ResultsAmong 370 drinking water samples, Salmonella Typhi was detected in 7 samples (1.8%) and Salmonella Paratyphi A was detected in 4 (1.0%) samples. Among 380 river water samples, Salmonella Typhi was detected in 171 (45%) and Salmonella Paratyphi A was detected in 152 (42%) samples. Samples located upstream of the Kathmandu city center were positive for Salmonella Typhi 12% of the time while samples from locations in and downstream were positive 58% and 67% of the time respectively. Individuals were observed bathing, washing clothes, and washing vegetables in the rivers.ImplicationsThese results suggest that drinking water was not the dominant pathway of transmission of Salmonella Typhi and Salmonella Paratyphi A in the Kathmandu Valley in 2019. The high degree of river water contamination and its use for washing vegetables raises the possibility that river systems represent an important source of typhoid exposure in Kathmandu